Organic light emitting diode (OLED) component has been widely used for its advantages such as good self-luminescence, high contrast, rapid response, and flexible display. A traditional OLED is made through vacuum evaporation technology. At present, mass production can be realized. However, in the technology, a fine mask is needed, which leads to low material utilization. Besides, with respect to large-sized panels, there are many challenges in the manufacturing technology of the mask. In recent years, printing display technology (ink jet printing, IJP) has been developed rapidly. IJP is a best way to realize large-size and low cost production of OLED.
To produce an OLED by IJP, it is necessary to modify a pixel definition layer and a substrate electrode, so that ink can fall into a pixel accurately and no overflow phenomenon occurs. In the prior art, flow spread of ink droplets in different cross sections is researched, and a substrate is performed by hydrophilic or hydrophobic patterning. The droplets will flow to a hydrophilic interface at a certain landing speed, and has a function of forming a trace pattern. Therefore, the substrate electrode and the pixel definition layer which contact the ink can be performed by hydrophilic or hydrophobic patterning (the substrate electrode is an ITO, i.e., a hydrophilic surface, while the pixel definition layer is a hydrophobic surface), so that the ink flows into the pixel.
In a process of manufacturing an OLED component, in order to prevent the cover from damaging the OLED component (for example, a cathode layer, a polarizer, etc.) when the cover is impacted by an external force, and to enable the entire component to have a certain pressure resistance, in the prior art, a plurality of photo spacers are usually arranged on a TFT substrate. The photo spacers have another function, i.e., they can maintain a cell thickness uniformity of a large-sized panel so as to avoid the occurrence of Newton rings.
A surface of the pixel definition layer on the substrate used in the OLED produced by IJP is hydrophobic, and a photo spacer is usually made of an organic photoresist, which cannot spread on a hydrophobic surface. In general, the photo spacer is formed on the cover. In this manner, there is a high requirement for an alignment accuracy of a device, and thus the device is difficult to be manufactured.